The present invention relates to an air conditioning apparatus for an automotive vehicle or the like comprising means for automatically sensing when the level of refrigerant fluid is low and de-energizing the apparatus in response thereto.
An air conditioning system for a motor vehicle or the like generally comprises a reservoir for refrigerant fluid. A compressor compressively liquifies the fluid from the reservoir and feeds it through a refrigerant circuit for cooling a cabin of the vehicle.
The operation of the system is controlled by a thermal switch which senses the temperature in the cabin or at the outlet of an evaporator and de-energizes the compressor when the temperature drops below a predetermined value. When the temperature again rises above the predetermined value, the compressor is again energized.
It is also known to sense the level of fluid in the reservoir and de-energize the air conditioning system when the level drops below a predetermined level due to leakage of fluid from the system. However, the prior art system suffers from the drawback in that the level of refrigerant in the reservoir tends to drop below the predetermined level when the compressor is stopped even though the amount of refrigerant in the system is sufficient. This makes it impossible to start the compressor and thereby operate the air conditioning system.